Improvement in screw-propellers



W. W. SHOE. Screw-Propeller.

No.198,052. Patented Dec. 11,1877

d e e lain/mm WSW UNITED STATES PATENT OEEIoE.

WILLIAM W. SHOE, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN SCREW-PROPELLER S.

Specification forming part of Letters PatentN'o. 198,052, dated December 11, 1877; application filed November 19, 1877.

To all whom it may concern:

Be it known that I, WILLIAM W. SHOE, of Philadelphia, Pennsylvania, have invented a new and useful Improvement in Propellers, of which the following is a specification:

The main object of my invention is to con- 'struct a cheap and strong propeller, a further object being to increase the effective workingsurface of the blade; and these objects I attain in the manner which I will now proceed to describe, reference being had to the accompanying drawing, in which- Figure 1 is a perspective view of the hub of the propeller; Fig. 2, a face view of the same; Fig. 3, a side view of the complete propeller; Fig. 4, a sectional view of part of the same, and Fig. 5 a sectional view of a modification.

-A is the propeller-shaft, and B a hub secured to the end of the same and provided, in the presentinstance, with four projecting arms, a, the rear faces of which are inclined in respect to a vertical plane, 02, passing through the shaft A, as shown in Fig.3.

The propeller-shaft extends entirely through the hub, and its rear end is recessed, so as to form continuations of the inclined faces of the projecting arms of the hub. (See Fig. 1.)

Each blade D consists of a central-plate, b, re-enforced throughout about two-thirds of its length by supplementary plates (1, the plates b and d being riveted or otherwise firmly secured together.

The blades are so formed at the inner ends as to correspond with the form of the rear faces of the arms a of the .hub, to which they are secured by bolts 6, the'extreme inner end of the blade overlapping a portion of the end of the shaft A, and being secured directly to the same by a bolt, 2'.

By making the hub of my improved propeller of cast metal and the blades of wrought metal firmly bolted to the hub and to the propeller-shaft, great strength will be secured,

and yet the propeller will be much lighter and I with advantage to propellers the blades of which are cast with the hub.

The use of strengtheningplates d on both sides of the central plate I) of each blade D is not essential to my invention, as the said plates d might be applied to one side only of the main plate, or in some cases said plate b might be so formed that the strengthening-plates 01 could be dispensed with altogether. Their use, however, is preferred.

In the modification, Fig. 5, the outer end of the arm a of the hub is made abrupt, so as to form a shoulder, to which the bent end of the inner re-enibrcing-plate all may be bolted, in order to secure additional strength.

I claim as my invention- 1. The combination, in a propeller, of detachable blades D with a hub, B, having arms at, whose rear faces are inclined in respect to a vertical plane passing through the propellershaft.

,2. The combination, in a propeller, of a hub through which the propeller-shaft passes, with detachable blades secured to the hub and to the shaft, as set forth.

3. A propeller-hub having arms a with inclined rear faces, substantially as set forth.

In testimonywhereof I have signed myname to this specification in the presence of two subscribing witnesses.

WM. W. SHOE. Witnesses:

RICHARD L. GARDINER, HARRY SMITH. 

